Sutureless wound closure

ABSTRACT

The present invention resides in a sutureless wound closure device for external use. The device comprises a base layer for fixing the device to skin and an upper layer. The base layer includes an aperture therein. The upper layer has a first end anchored to the base layer and a second, opposite end that includes fixing means to attach the end to the base layer and close the aperture in the base layer.

The present invention relates to a device and technique to close woundswithout the use of sutures.

Surgery requires cutting of the skin to reveal underlying tissues onwhich medical intervention is required. An increasingly popularalternative to open surgery is keyhole surgery, in which a number ofsmall incisions or punctures of typically 5 to 10 mm in length are madeto allow access to the underlying tissues and body structures. Surgeryis then carried out using hand-held or robotically controlled telescopesand micro-instruments. There are a number of advantages for a patientwith keyhole surgery versus an open procedure. These include reducedpain due to smaller incisions, reduced tissue damage and shorterrecovery time.

Keyhole surgery usually results in multiple small incisions. Surgeonshave a number of options in terms of wound closure once surgery iscompleted. The most time efficient method for the surgeon is to leavethe wounds to heal on their own, particularly smaller wounds. However,the wounds usually weep and typically require redressing. The wound mayalso not repair cleanly, leaving visible scarring.

While a simple dressing may be applied to the wound to soak up anyseepage, such a dressing will not close the wound, which is particularlyimportant because, whilst the incision will be made in a straight line,the aperture will have become elliptical during surgery and so needs tobe returned to a straight line to reduce wound seepage and limitscarring.

Some surgeons prefer suturing of the wounds, particularly the largerwounds (10-15 mm). Suturing is technically difficult especially in thesmaller wounds and is therefore time consuming. Sutures themselves havea financial cost and leave a foreign material within the wound which isa nidus for infection. If non absorbable sutures are used, the sutureneeds to be removed at some stage following the surgery (typically 5-10days) and the sutures themselves may produce scarring compromising thecosmetic result. Absorbable sutures although not requiring removal, mayproduce an inflammatory reaction in some patients.

An alternative technique of wound closure is the use of so called“butterfly stitches”. Typical commercially available products areSteri-Strips™ or Micropore™ Surgical Tape. Steri-Strips are thinadhesive strips reinforced with polyester filaments that are appliedacross a laceration. The primary purpose of applying a Steri-Strip typeproduct across a wound opening is to close the wound and prevent thewound from opening further. The way in which this is done typicallyinvolves placing the adhesive Steri-Strip onto either side of the woundin a manner that pulls the skin on either side of the wound together.Steri-Strips lessen scarring, reduce the chance of infection compared tosutures or staples, provide wound support and are easier to care for.

However, there are two big drawbacks of using Steri-strips to closesmall wounds, particularly those resulting from keyhole surgery.Firstly, wounds from keyhole surgery notoriously weep fluids (blood andother fluids like saline, used to irrigate during surgery). When aSteri-strip is used, fluid exudes from the wound as it is squeezed shut.As the Steri-Strip is placed across the wound, this fluid wicks alongboth axes of the Steri-Strip, dramatically reducing adhesive propertiesof the Steri-Strip and preventing adequate skin adhesion to maintainwound closure.

Secondly, whilst a Steri-Strip, correctly applied across a wound, canprevent a wound from opening further, they do not provide an easy andreproducible method of closing the wound edges to encourage scar freehealing and reduced risk of infection.

U.S. Pat. No. 7,927,347 describes and array of existing suturelessdevices, as well as the device claimed therein. For example, U.S. Pat.No. 3,971,384 describes a surgical closure device having two pieces ofsurgical tape that are secured on each side of a wound. One piece oftape has an anchor for a tie strip secured to it while the other pieceof tape has a slide secured to it. The tie strip has ratchet teeth onits dorsal surface so that the strip is inserted through the anchor end,across the wound and into the ratchet. The tape is then tightened andlocked with the ratchet bringing the two sides of the wound together.This a cumbersome and complicated piece of equipment more suited tolengthy wounds and as such is deemed as unsuitable for small puncturewounds as found in keyhole surgery.

U.S. Pat. No. 4,924,866 describes a wound closure device comprising twoarms connected by a hinged joint. The arms each have a single pair of“skin engaging members” on the ventral surface so that, when the deviceis placed over a wound, the skin engaging members enter the skin,pulling the wound together underneath the joint. Not only is this devicelimited in its pliability because of the structure of the arms, but theuse of barbs in close proximity to the wound brings its wound closureability into question. The lack of a ratchet mechanism also means thatthe edges of the wound must be juxtaposed before the device is applied.Last but not least, such a device is rather bulky and clunky for a smallwound closure.

U.S. Pat. No. 7,927,347 itself describes a surgical fastener which isadhered to the skin by barbs and closes the two sides of a wound by wayof male and female interconnecting straps that are tensioned using aratchet mechanism. Again, the device itself is bulky and overcomplicated for the task in hand.

Thus, there is a need for sutureless wound closures that are effectivewhen used in a damp or moist environment and employ a swift and durableapplication technique.

Accordingly, the present invention resides in a simple wound closuredevice that is quick to apply, simple, quick and effective to operateand cheap to manufacture.

In particular, the present invention resides in a sutureless woundclosure device comprising: a) a base layer for attaching the device toskin; and b) an upper tensioning layer having a first end anchored tothe base layer and a second, opposite end including fixing means toattach the end to the base layer, wherein the base layer includes anaperture that, in use, is covered by the upper tensioning layer.

The base layer provides a firm attachment for the device on the skin andthe aperture allows any exudate or fluid to escape from the woundwithout being wicked along the base layer and causing the base layer tobe released from the skin. The upper layer covers the aperture andallows the sides of the wound or incision to be juxtaposed andsubstantially closed through tension of the upper layer on the baselayer. The aperture also acts to support the wound or incision while itheals, and substantially prevents bunching of redundant dressing whentension is applied to the upper tensioning layer.

The device is for external use to close a wound or incision in the skin.

The base layer may be any suitable shape but is preferably substantiallyrectangular in shape having a length greater than its width.

It will be appreciated that the base layer needs to be attachable to theskin in a non-permanent fashion. However, the bond between the skin andbase layer should be strong enough to allow the device to remain inposition for a suitable number of days or weeks, without moving orbecoming dislodged by clothing or washing, to allow the wound to closeand heal sufficiently. Thus, ideally, the base layer includes a(hypoallergenic) self-adhesive layer but may equally well includeadhesive, barbs or microneedles on its skin-facing surface to attach thedevice to the skin.

The base layer may be made from any suitable material, such as anon-woven, paper-based material such as that used for surgical tape orMicropore™. If such a material is used, then it may be necessary toreinforce the material, for example by using polyester filaments runningthe length of the base layer, as used in Steri-strips. Alternatively,the base layer may be made from a plasticised material or a polymer thathas suitable strength and durability for the intended use. In essence,because the base layer includes an aperture, it should be constructedfrom a material that has sufficient integral strength to withstand theinclusion of an aperture therein.

For ease of location of the device in use, the aperture is preferablylocated substantially centrally in the width and length of the baselayer. However, it will be appreciated that the aperture may be locatedanywhere along the length and/or width of the device, provided that thebase layer maintains sufficient integral strength; i.e. is not prone totearing in use.

The aperture may be of any suitable shape and size. In use, the apertureis ideally sized substantially to surround an incision or wound in theskin. In particular, a substantially elliptical shape, orientatedperpendicular to the length of the base layer, is believed to be theoptimum shape. In this way, the user is able to view the wound orincision through the aperture to ensure that the wound is correctlypositioned with respect to the aperture and supported by the base layerwhen applied to the skin. Also, since a straight incision will becomeelliptical during surgery, the base layer aperture will roughly mimicthe shape of the wound and, as will be explained later, will enable anaccurate juxtaposition of the two opposing sides of the incision/wound.

The aperture may be of any suitable dimension and may even simply be inthe form of guide slits so that an aperture of desired size may becreated in the base layer. For use in closing keyhole surgery punctures,an aperture size of between about 5 and about 15 mm in length isdesirable. Open surgery incisions are typically larger and so the baselayer and aperture may be suitably dimensioned for use in the closure ofsuch incisions. While it is preferred if the aperture fully surroundsthe incision or wound, there may be circumstances where this is notdesirable or possible. In which case, the aperture size should beselected to be as close to the wound or incision length as possible,with some overlap of the base layer with each end of the incision/woundbeing tolerated. Alternatively, or in addition, multiple strips may beused to close the wound in a side by side configuration.

It may be desirable to impregnate the base layer or coat the skin-facingsurface of the base layer with one or more compositions that promote oraid wound healing, reduce or minimise the likelihood of infection,and/or decrease or minimise the growth of scar tissue. Such compositionsmay include cytokines, growth hormones, collagen, anti-inflammatories,antiseptics and/or antibiotics.

The upper layer of the device is anchored at one end to the base layer.As with the base layer, the upper layer may be of any suitable shapebut, ideally, is of a similar or corresponding shape and dimension tothe base layer. In this way, there are fewer edges to catch on clothesetc and become unstuck. The first end of the upper layer should beanchored as permanently as possible to the base layer on one side of theaperture. For example, the end may be (heat) fused, glued or stitched tothe base layer, or may be woven from the base layer. This provides afirm anchor which may be used to tension the device.

It will be appreciated that the end will be fixed in a location off-setfrom the aperture. However, to ensure maximum scope for tensioning ofthe device (see below) and to reduce puckering of the skin and devicearound the aperture, the upper end is ideally anchored next to oradjacent the aperture and, therefore, in practice next to or adjacentthe wound or incision edge. Alternatively, the end may be anchored closeor proximate to the aperture. The greater the distance between theaperture and the anchor point, the greater the likelihood of puckering(and subsequent discomfort for the patient) and lower the tensionapplied over the aperture.

The second, opposite end of the upper layer is a free end that, in use,is fixed to the base layer so the upper layer covers and substantiallycloses the aperture. The fixing means on the free end may be of anysuitable means, such as adhesive, self-adhesive, Velcro®, barbs ormicroneedles. As with the base layer, the fixing means should havesufficient strength to hold the upper layer free end onto the base layerfor the duration in which the device needs to be applied to the skin.

It is advantageous if the upper layer includes a dressing, such as anabsorbent pad in the region where the upper layer overlays the aperture.The dressing absorbs any seepage from the wound and substantiallyprevents moisture from wicking between the upper and base layers,resulting in release of the upper layer from the base layer as well asapplying a protective covering.

The dressing may include one or more compositions to promote or aidwound healing, reduce or prevent bacterial or fungal infection, and/orreduce the likelihood of scar tissue development. For example, thedressing may be an alginate dressing to maintain a moist atmosphere,absorb wound secretions, minimise bacterial contamination and promotehealing and the formation of granulation tissue.

In use, the base layer is fixed to the skin so that the aperturesurrounds the wound. The base layer is aligned so that the wound isoriented in the aperture perpendicular to the upper layer of the device.

The free end of the upper layer is then pulled in a direction away fromthe anchored end so the size of the base layer aperture is reduced,bringing the two sides of the wound together and closing the wound. Oncethe wound has been closed, the free end is fixed to the base layer,without releasing the tension, thereby covering the aperture and wound.

The present invention will now be described in more detail by way ofnon-limiting example with reference to the figures, in which:

FIG. 1 is a plan view from above of the device of the present inventionwhen closed;

FIG. 2 is a perspective view of the device from above, showing thedevice in an open configuration;

FIG. 3 is a section along line A-A of FIG. 1 showing the device attachedto the skin in an open configuration;

FIG. 4 is a perspective view of the device from above illustratingtensioning of the upper layer;

FIG. 5 is a section along line A-A of FIG. 1 showing the device attachedto the skin in a partly closed configuration;

FIG. 6 is a perspective view of the device from above showing the devicein a tensioned configuration before the aperture is closed by the upperlayer;

FIG. 7 is a section along line A-A of FIG. 1 showing the device attachedto the skin in a closed configuration;

FIG. 8 is a perspective view from above illustrating the device whenclosed in situ;

FIG. 9 is a perspective view of an alternative embodiment of the devicefrom above, showing the device in an open configuration; and

FIG. 10 is a perspective view from above illustrating the alternativeembodiment of the device when closed in situ.

The sutureless wound closure device of the present invention is based ona standard adhesive plaster such as a BandAid®. As shown in FIGS. 1 and2, the device 1 has a base layer 2, an aperture 3 in the base layer 2and an upper layer 4. In the example illustrated, the device alsoincludes a dressing 5 in the form of an absorbent pad.

The base layer 2 is rectangular in shape having a length that is greaterthan its width. The layer is made from a porous, non-woven backing whichis reinforced with polyester filaments 6. The skin-facing surface iscoated with a pressure-sensitive, hypoallergenic adhesive that, in use,adheres the base layer to the skin once a protective backing paper hasbeen removed.

Located in the centre of the base layer 2 is an aperture 3. The aperture3 is elliptical in shape with the long axis of the ellipse beingorientated perpendicular to the length of the base layer 2. In theparticular embodiment illustrated, the width of the base layer 2 isdimensioned so that there are two reinforcing filaments 6 on either sideof the aperture 3. This ensures that the base layer 2 has sufficientintegral strength around the aperture 3. It will be appreciated that thenumber of reinforcing filaments, if present, will be varied according tothe width, desired use, and required strength of the base layer.

The upper layer 4 of the device 1 is similarly dimensioned to the baselayer 2 and is made from the same material as the base layer 2. In theembodiment shown in the figures, the upper layer 4 has a length that isapproximately three quarters that of the base layer 2. One end 4 a ofthe upper layer 4 is anchored to the upper surface (in use) of the baselayer 2 so that an anchor point is located near to the aperture 3 at adistance that is approximately half the width of the aperture 3. End 4 ais permanently fixed to the base layer 2 through heat fusion of the twolayers. In this way, end 4 a cannot be release from the base layer 2.

The opposite end 4 b of the upper layer 4 is a free end that has, at itsdistal portion, a coating of pressure-sensitive self-adhesive on thesurface that faces the base layer 2. In between the fixed end 4 a andthe self-adhesive end 4 b is an absorbent pad or dressing 5.

FIGS. 3 to 8 illustrate the device in use. Starting with FIG. 3, thebase layer 2 of the device 1 is fixed to the surface of the skin 10 sothat the aperture 3 is located around or at the open edges of a wound11. Upper layer end 4 a can be seen anchored to the base layer 2 whilethe free end 4 b is not fixed, allowing the user to see the location ofthe aperture 3.

Turning to FIG. 4, once the base layer 2 has been suitably located, thefree end 4 b of the upper layer 4 is grasped by the user and pulled inthe direction of Arrow X in the plane of the length of the base layer 2and perpendicular to the direction of the wound 11. As can be seen inthis figure and in FIG. 5, the pulling force narrows the aperture 3 andpulls the sides of the wound 11 towards each other, thereby closing thewound 11.

As shown in FIG. 6, tension is maintained on the free end 4 b of theupper layer 4 as the upper layer 4 is lowered towards the base layer 2.

FIGS. 7 and 8 show the device in a closed configuration in which thesides of the wound 11 are held together and dressing 5 covers theaperture 3. The dressing 5 is located to capture any seepage from thewound 11 so that capillary forces between the base and upper layers 2, 4do not come into effect, fluid is not wicked between the layers, and sothe seal between the upper and lower layers 2, 4 is maintained.

As shown in FIG. 8, adhesion of the upper layer 4 to the base layer 2maintains a tension (illustrated by Arrows X and Y) on both sides of thewound 11, keeping the wound 11 closed and allowing the cut skin to knittogether and heal with minimal scar formation.

In an alternative embodiment, the base layer 2 further includes aflexible portion 15 on either side of the aperture 3. In the embodimentshown in FIG. 9, the flexible portion 15 is made from a thinner materialthan the base layer 2 and has no or minimal adhesive. This allows theflexible portion 15 to concertina or fold upwards away from the skinwhen the aperture 3 is closed by the top layer 4. The top layer 4 isdimensioned such that flexible portion 15 is able to fold upwards oneither side of the top layer 4, as illustrated in FIG. 10. Inparticular, the top layer 4 is dimensioned to have a width thatsubstantially matches the width or diameter of the aperture 3. In thisway, the device 1 does not fold the underlying skin, thereby enhancingthe effectiveness of the device 1 on the skin and adding comfort to thepatient. An alternative to the flexible portion 15 could be a waistedportion.

The present invention finds particular application in the field ofkeyhole surgery but it will be appreciated that the closure device maybe equally suitably used for larger wounds, such as medium-sized opensurgery wounds of a size say about 10-15 mm. Equally, a large or largerwound may be closed using a number of closure devices of the presentinvention.

1. A sutureless wound closure device comprising: a) a base layer forattaching the device to skin; and b) an upper tensioning layer having afirst end anchored to the base layer and a second, opposite endincluding fixing means to attach the end to the base layer, wherein thebase layer includes an aperture that, in use, is covered by the uppertensioning layer.
 2. A device according to claim 1, wherein the baselayer is substantially rectangular in shape having a length greater thanits width.
 3. A device according to claim 1, wherein the base layerincludes adhesive, self-adhesive, barbs or microneedles on itsskin-facing surface to attach the device to the skin.
 4. A deviceaccording to claim 1, wherein the aperture in the base layer issubstantially centrally located in the width and length of the baselayer.
 5. A device according to claim 1, wherein the aperture is sizedsubstantially to surround an incision or wound in the skin.
 6. A deviceaccording to claim 1, wherein the aperture has a substantiallyelliptical shape, orientated perpendicular to the length of the baselayer.
 7. A device according to claim 1, wherein the aperture is between3 and 15 mm in length.
 8. A device according to claim 1, wherein thebase layer includes one or more compositions to promote or aid woundhealing, reduce or minimise the likelihood of infection, and/or decreaseor minimise the growth of scar tissue.
 9. A device according to claim 1,wherein the first end of the upper tensioning layer is anchored to thebase layer on one side of the aperture.
 10. A device according to claim9, wherein the first end of the upper layer is anchored next to theaperture.
 11. A device according to claim 9, wherein the first end ofthe upper layer is anchored proximate to the aperture.
 12. A deviceaccording to claim 1, wherein the fixing means on the second end of theupper layer are adhesive, self-adhesive, Velcro®, barbs or microneedles.13. A device according to claim 1, wherein the upper layer furtherincludes a dressing located to cover the aperture when in use.
 14. Adevice according to claim 13, wherein the dressing includes at least onecomposition to promote or aid wound healing, reduce or minimise thelikelihood of infection, and/or decrease or minimise the growth of scartissue.
 15. A device according to claim 1, wherein the base layerincludes a flexible portion on either side of the aperture.
 16. A deviceaccording to claim 15, wherein the flexible portion does not attach tothe skin. 17-18. (canceled)